Tank



FIG. 1 is a top plan view of a tank showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is an elevational view taken from one side thereof, the opposite side being a mirror image of the side shown; and

FIG. 6 is a perspective view taken from the top, front and one side thereof. 

The ornamental design for a tank, as shown and described. 